Abstract

We investigate the tight focusing properties of a double-ring-shaped, azimuthally polarized vector beam (DRS-APVB) by use of vectorial Debye theory. It is shown that a dark channel with an ultralong depth of focus (∼106λ) and subwavelength focal holes (∼0.5λ) can be generated by focusing a DRS-APVB through a dielectric interface with an annular high-numerical aperture (NA) objective lens. The influence of the NA of the objective, the relative refractive indices of two dielectric media, and the probe depth of the system on the focusing properties of the dark channel has been studied in detail. Such a non-diffracting dark channel could find potential applications in atom optical experiments, such as with atomic lenses, atom traps, and atom switches.

Cited By

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.